AbstractThe Kamlet–Taft solvent parameters of solvate ionic liquids (SILs) prepared from lithium salts with glyme and glycol ligands are determined. The dipolarity/polarisibilities (π*) are high, similar to those found in conventional ionic liquids. The H‐bond basicities (β) depend strongly on the anion. The H‐bond acidities (α) are high in both glyme and glycol SILs, indicating that the lithium is acting as a H‐bond donor site. “Poor” SILs have glyme‐rich and salt‐rich regions. In these liquids the π* and β values are almost identical to the parent glyme or glycol, and the α values are determined by the salt alone.